The Nutrition Support Shared Resource provides dietary assessment information to support diet-related cancer research studies. Investigators in both the Cancer Etiology Program and the Cancer Prevention and Control Program are given assistance with the development of dietary assessment instruments, training of project staff, and the interpretation of diet/nutrition data. The Shared Resource also supports other local, national, and international diet-related projects, upon request. The resource remains unique in its ability to access comprehensive food and dietary supplement composition databases customized to the multiethnic population of Hawaii, along with other ethnic groups in Los Angeles and the Pacific Islands. The structure of these databases allows for frequent updates, as well as additions of nutrients and food components as new hypotheses are developed by CRCH investigators. Numerous dietary questionnaires, appropriate for studies of specific cancers, have been developed and are widely used by investigators within the CRCH, as well as in collaborating institutions. The staff of the resource maintains food composition, supplement composition, and recipe databases, trains interviewers on appropriate data collection methods, designs new dietary questionnaires, and reviews the accuracy of dietary recalls, food records, and questionnaires from the various studies. The CCSG provides stability for these activities and ensures that the resource remains in the forefront of dietary assessment methodology when providing assistance to CRCH investigators.